Johannesburg is 1-2 hours ahead of London. London uses GMT/BST while Johannesburg uses South Africa Standard Time (SAST, UTC+2). When it's 12:00 PM in London, it's 2:00 PM in Johannesburg.
South Africa does not observe daylight saving time, but the UK does. The difference is 1 hour during British Summer Time and 2 hours during GMT.
Best calling time: 7:00 AM - 3:00 PM London time. This corresponds to 9:00 AM - 5:00 PM in Johannesburg, covering South African business hours.
London and Johannesburg are connected by direct flights taking about 11 hours. Johannesburg is Africa's largest economy hub and a major business destination with strong ties to the UK.